Tissue engineering is an emerging means for resolving the problems of tissue repair and organ replacement in regenerative medicine.Insufficient supply of nutrients and oxygen to cells in large-scale tissues has led to...Tissue engineering is an emerging means for resolving the problems of tissue repair and organ replacement in regenerative medicine.Insufficient supply of nutrients and oxygen to cells in large-scale tissues has led to the demand to prepare blood vessels.Scaffold-based tissue engineering approaches are effective methods to form new blood vessel tissues.The demand for blood vessels prompts systematic research on fabrication strategies of vascular scaffolds for tissue engineering.Recent advances in 3D printing have facilitated fabrication of vascular scaffolds,contributing to broad prospects for tissue vascularization.This review presents state of the art on modeling methods,print materials and preparation processes for fabrication of vascular scaffolds,and discusses the advantages and application fields of each method.Specially,significance and importance of scaffold-based tissue engineering for vascular regeneration are emphasized.Print materials and preparation processes are discussed in detail.And a focus is placed on preparation processes based on 3D printing technologies and traditional manufacturing technologies including casting,electrospinning,and Lego-like construction.And related studies are exemplified.Transformation of vascular scaffolds to clinical application is discussed.Also,four trends of 3D printing of tissue engineering vascular scaffolds are presented,including machine learning,near-infrared photopolymerization,4D printing,and combination of self-assembly and 3D printing-based methods.展开更多
The study of Electromagnetic Compatibility is essential to ensure the harmonious operation of electronic equipment in a shared environment. The basic principles of Electromagnetic Compatibility focus on the ability of...The study of Electromagnetic Compatibility is essential to ensure the harmonious operation of electronic equipment in a shared environment. The basic principles of Electromagnetic Compatibility focus on the ability of devices to withstand electromagnetic disturbances and not produce disturbances that could affect other systems. Imperceptible in most work situations, electromagnetic fields can, beyond certain thresholds, have effects on human health. The objective of the present article is focused on the modeling analysis of the influence of geometric parameters of industrial static converters radiated electromagnetic fields using Maxwell’s equations. To do this we used the analytical formalism for calculating the electromagnetic field emitted by a filiform conductor, to model the electromagnetic radiation of this device in the spatio-temporal domain. The interactions of electromagnetic waves with human bodies are complex and depend on several factors linked to the characteristics of the incident wave. To model these interactions, we implemented the physical laws of electromagnetic wave propagation based on Maxwell’s and bio-heat equations to obtain consistent results. These obtained models allowed us to evaluate the spatial profile of induced current and temperature of biological tissue during exposure to electromagnetic waves generated by this system. The simulation 2D results obtained from computer tools show that the temperature variation and current induced by the electromagnetic field can have a very significant influence on the life of biological tissue. The paper provides a comprehensive analysis using advanced mathematical models to evaluate the influence of electromagnetic fields. The findings have direct implications for workplace safety, potentially influencing standards and regulations concerning electromagnetic exposure in industrial settings.展开更多
Artificial bone with porous structure is crucial for tissue scaffold and clinic implants.Scaffold provides structure support for cells and guides tissues regeneration for final tissue structure.A computational aided p...Artificial bone with porous structure is crucial for tissue scaffold and clinic implants.Scaffold provides structure support for cells and guides tissues regeneration for final tissue structure.A computational aided process of porous bone modeling was developed which described the design and fabrication of tissue scaffolds by considering intricate architecture,porosity and pore size.To simulate intricate bone structure,different constructive units were presented.In modeling process,bone contour was gotten from computed tomography(CT)images and was divided into two levels.Each level was represented by relatively reconstructive process.Pore size distribution was controlled by using mesh generation.The whole hexahedral mesh was reduced by unit structure,when a 3D mesh with various hexahedral elements was provided.The simulation results show that constructive structure of porous scaffold can meet the needs of clinic implants in accurate and controlled way.展开更多
Epithelial cell networks imply a packing geometry characterized by various cell shapes and distributions in terms of number of cell neighbors and areas.Despite such simple characteristics describing cell sheets,the fo...Epithelial cell networks imply a packing geometry characterized by various cell shapes and distributions in terms of number of cell neighbors and areas.Despite such simple characteristics describing cell sheets,the formation of bubble-like cells during the morphogenesis of epithelial tissues remains poorly understood.This study proposes a topological mathematical model of morphogenesis in a squamous epithelial.We introduce a new potential that takes into account not only the elasticity of cell perimeter and area but also the elasticity of their internal angles.Additionally,we incorporate an integral equation for chemical signaling,allowing us to consider chemo-mechanical cell interactions.In addition to the listed factors,the model takes into account essential processes in real epithelial,such as cell proliferation and intercalation.The presented mathematical model has yielded novel insights into the packing of epithelial sheets.It has been found that there are two main states:one consists of cells of the same size,and the other consists of“bubble”cells.An example is provided of the possibility of accounting for chemo-mechanical interactions in a multicellular environment.The introduction of a parameter determining the flexibility of cell shapes enables the modeling of more complex cell behaviors,such as considering change of cell phenotype.The developed mathematical model of morphogenesis of squamous epithelium allows progress in understanding the processes of formation of cell networks.The results obtained from mathematical modeling are of significant importance for understanding the mechanisms of morphogenesis and development of epithelial tissues.Additionally,the obtained results can be applied in developing methods to influence morphogenetic processes in medical applications.展开更多
A modeling strategy to predict the ability of surgical clips to achieve mechanical hemostasis when applied to the cut edge of a thick and muscular tissue is presented in this work. Although such a model may have broad...A modeling strategy to predict the ability of surgical clips to achieve mechanical hemostasis when applied to the cut edge of a thick and muscular tissue is presented in this work. Although such a model may have broad utility in the design of hemostatic clips and other surgical and wound closure applications, our particular focus was on uterine closure following a Cesarean delivery. Mechanical closure of a blood vessel, which is the first step in the hemostatic process, is established when the compressive forces on the outer surface of a blood vessel are sufficient to overcome the local blood pressure and collapse the vessel. For thick tissue, forces applied to the tissue surface set up a stress distribution within the tissue that, if sufficient to mechanically close all vessels, will lead to cessation of local blood flow. The focus of the current work was on utilization of a planar and nonlinear finite element model to predict the pressure distribution within uterine tissue under the influence of hemostatic clips. After experimental model validation with a polymer tissue phantom, design curves were numerically developed, which consisted of the clip force necessary to achieve hemostasis for a given thickness tissue as well as the resulting deformed tissue thickness. Such curves could form the basis for a preliminary clip design, which would provide initial design guidance before more expensive experimental studies were required.展开更多
Paper devices have recently attracted considerable attention as a class of cost-effective cell culture substrates for various biomedical applications.The paper biomaterial can be used to partially mimic the in vivo ce...Paper devices have recently attracted considerable attention as a class of cost-effective cell culture substrates for various biomedical applications.The paper biomaterial can be used to partially mimic the in vivo cell microenvironments mainly due to its natural three-dimensional characteristic.The paper-based devices provide precise control over their structures as well as cell distributions,allowing recapitulation of certain interactions between the cells and the extracellular matrix.These features have shown great potential for the development of normal and diseased human tissue models.In this review,we discuss the fabrication of paper-based devices for in vitro tissue modeling,as well as the applications of these devices toward drug screening and personalized medicine.It is believed that paper as a biomaterial will play an essential role in the field of tissue model engineering due to its unique performances,such as good biocompatibility,eco-friendliness,cost-effectiveness,and amenability to various biodesign and manufacturing needs.展开更多
The main objective of this proposed article is to provide explanations to justify the validity of the results of the studies of the interaction between the electromagnetic fields and the human body. It can also find d...The main objective of this proposed article is to provide explanations to justify the validity of the results of the studies of the interaction between the electromagnetic fields and the human body. It can also find direct applications in the characterization and modeling of the macroscopic electrical properties of the biological media for assessing the effects of fields induced by electromagnetic radiation sources in the human body to set up new standards <span>on the Human exposure to electromagnetic fields. To do this, we have taken into account the different physical phenomena of propagation of a hyper-frequency electromagnetic plane wave and on the other hand, the expe</span>rimental values <span></span><span><span><span style="font-family:;" "="">in order to model the electrical behavior of human biological tissues based on an equivalent electronic circuit model composed of capacities, resistance and reel, which assimilates the biological tissues of the skin, grease, blood. This model using the characteristic impedance of the dielectric support makes it possible to evaluate the voltage induced by the electromagnetic waves of the hyper-frequencies in the studied biological system. The results of the simulations obtained from computer tools demonstrate that the hyper-frequency electromagnetic waves can result in an elevation of the electrical potential of the biological tissues. Despite this potential is a decreasing function of the penetration depth.</span></span></span>展开更多
Digital light processing(DLP)-based bioprinting technology has recently aroused considerable concerns as a strategy to deliver biomedical materials and/or specific cells to create sophisticated structures for various ...Digital light processing(DLP)-based bioprinting technology has recently aroused considerable concerns as a strategy to deliver biomedical materials and/or specific cells to create sophisticated structures for various tissue modeling and regeneration.In this review,we display a concise introduction of DLP bioprinting,and a further discussion on the design and manufacture of DLP(bio)printer with varied bioinks and their biomedical applications toward drug screening,disease modeling,tissue repair,and regenerative medicine.Finally,the advantages,challenges,and perspectives of the DLP printing platforms are detailed.It is believed that DLP bioprinting will play a decisive role in the field of tissue model and regenerative medicine,mainly due to its time-efficient,higher resolution,and amenability to automation for various tissue needs.展开更多
This paper presents a novel method for assisting surgeons in automatically computing an optimal surgical plan by directly specifying the desired correction to a facial outline. First, the desired facial appearance is ...This paper presents a novel method for assisting surgeons in automatically computing an optimal surgical plan by directly specifying the desired correction to a facial outline. First, the desired facial appearance is designed using a 3D sculpturing tool, while the cut regions of the skull are defined based on facial anatomy. Then, the deformation of the face meshes is performed using an improved biomechanical model in which virtual external forces are driven by the displacements corresponding to the differences of node coordinates between the original and specified face meshes, and free nodes and fixed nodes are defined in terms of the contact surfaces between the soft tissues and the bones within the cut regions. Finally, the shape of the contact surfaces is updated following the deformation of the soft tissues. After registering the deformable contact surfaces and the cut surfaces, the final positions of the cut bones are estimated. Evaluation of preliminary experimental results quantitatively shows the effectiveness of the proposed approach.展开更多
This article introduces a new biomedical / open surgical instrument to assist surgeon in applying surgical clips to patient’s body tissue and blood vessel during surgical processes. The new clip delivery system is de...This article introduces a new biomedical / open surgical instrument to assist surgeon in applying surgical clips to patient’s body tissue and blood vessel during surgical processes. The new clip delivery system is designed to better the clip’s distal advance through internal clip channel, jaw guiding track, and all other transition areas to keep surgical clip from accidental shooting out during clip’s distal move into jaws. Currently the clip distal move in normal surgical instrument is usually driven by compression springs and some complains of clip accidental drop-off were recorded in surgical procedures. Because higher request of dimensional tolerance and better component surface quality are needed in case the compression springs are used as driven force, a little dimensional devia-tion or less qualified part surface produced from manufacturing processes will potentially cause surgical clip device malfunction or misfiring of the clips. It is clearly known that the jaws can seriously sever or damage patient’s blood ves-sel or body tissue if there is no clip inside the jaws due to accidental clip drop-off, when surgeons close instrument handles. The improved internal system design in this new open surgical instrument can prevent clip from accidental drop-off because of well guided and controlled clip distal move through internal clip channel and track. Besides the operational force to fully form clip is lower than existing surgical clip devices due to better mechanical advantage in this new instrument design. In addition to the above, manufacturing and product cost can be decreased since lower requirement of dimensional tolerance and surface quality of instrumental parts is allowed in this new surgical instrument design. This new instrumental prototype is build upon the analysis of computer aided modeling and simulation to prove its good mechanical advantage, feasible function, reliable performance. The preliminary results of instrument fir-ing force from both computer aided modeling and prototype testin展开更多
This paper studied experimentally and theoretically the biomechanical properties of skin with laser influence. Different types of tensile tests of the porcine skin in vitro were conducted to study effect of the laser,...This paper studied experimentally and theoretically the biomechanical properties of skin with laser influence. Different types of tensile tests of the porcine skin in vitro were conducted to study effect of the laser, tensile strength, stress-strain relationship, influence of skin's anisotropy and different regions, repetitive loading and stress-relaxation. A modeling of skin was developed according to the experimental results. The modeling provided insights into the important structure-function relationship in skin tissue with the laser effect. The nonlinear and anisotropic mechanical responses of skin are largely due to varying degree of fiber undulation which is effected by laser and outside forces. By introducing the laser factor into the constitutive modeling, the skin's biomechanical properties and the mechanism of the skin repair with laser were discussed.展开更多
Tissue engineering’s main goal is to regenerate or replace tissues or organs that have been destroyed by disease,injury,or congenital disabilities.Tissue engineering now uses artificial supporting structures called s...Tissue engineering’s main goal is to regenerate or replace tissues or organs that have been destroyed by disease,injury,or congenital disabilities.Tissue engineering now uses artificial supporting structures called scaffolds to restore damaged tissues and organs.These are utilized to attach the right cells and then grow them.Rapid prototyping appears to be the most promising technology due to its high level of precision and control.Bone tissue replacement“scaffolding”is a common theme discussed in this article.The fused deposition technique was used to construct our scaffold,and a polymer called polylactic acids and soybean oil resin were used to construct our samples.The samples were then divided into two groups;the first group was left without immersion in the simulated body fluid and served as a control for comparison.The second group was immersed in the simulated body fluid.The results of the Field Emission Scanning Electron Microscope(FESEM),Energy Dispersive X-ray Spectroscopy(EDX)and X-ray diffraction(XRD)were utilized to interpret the surface attachment to ions,elements,and compounds,giving us a new perspective on scaffold architecture.In this study,an innovative method has been used to print therapeutic scaffold that combines fused deposition three-dimensional printing with ultraviolet curing to create a high-quality biodegradable polymeric scaffold.Finally,the results demonstrate that adding soybean oil resin to the PLA increased ion attachment to the surface while also attracting tricalcium phosphate formation on the surface of the scaffold,which is highly promising in bone tissue replacement.In conclusion,the soybean oil resin,which is new in the field of bone tissue engineering,shows magnificent characteristics and is a good replacement biopolymer that replaces many ceramic and polymeric materials used in this field that have poor morphological characteristics.展开更多
文摘Tissue engineering is an emerging means for resolving the problems of tissue repair and organ replacement in regenerative medicine.Insufficient supply of nutrients and oxygen to cells in large-scale tissues has led to the demand to prepare blood vessels.Scaffold-based tissue engineering approaches are effective methods to form new blood vessel tissues.The demand for blood vessels prompts systematic research on fabrication strategies of vascular scaffolds for tissue engineering.Recent advances in 3D printing have facilitated fabrication of vascular scaffolds,contributing to broad prospects for tissue vascularization.This review presents state of the art on modeling methods,print materials and preparation processes for fabrication of vascular scaffolds,and discusses the advantages and application fields of each method.Specially,significance and importance of scaffold-based tissue engineering for vascular regeneration are emphasized.Print materials and preparation processes are discussed in detail.And a focus is placed on preparation processes based on 3D printing technologies and traditional manufacturing technologies including casting,electrospinning,and Lego-like construction.And related studies are exemplified.Transformation of vascular scaffolds to clinical application is discussed.Also,four trends of 3D printing of tissue engineering vascular scaffolds are presented,including machine learning,near-infrared photopolymerization,4D printing,and combination of self-assembly and 3D printing-based methods.
文摘The study of Electromagnetic Compatibility is essential to ensure the harmonious operation of electronic equipment in a shared environment. The basic principles of Electromagnetic Compatibility focus on the ability of devices to withstand electromagnetic disturbances and not produce disturbances that could affect other systems. Imperceptible in most work situations, electromagnetic fields can, beyond certain thresholds, have effects on human health. The objective of the present article is focused on the modeling analysis of the influence of geometric parameters of industrial static converters radiated electromagnetic fields using Maxwell’s equations. To do this we used the analytical formalism for calculating the electromagnetic field emitted by a filiform conductor, to model the electromagnetic radiation of this device in the spatio-temporal domain. The interactions of electromagnetic waves with human bodies are complex and depend on several factors linked to the characteristics of the incident wave. To model these interactions, we implemented the physical laws of electromagnetic wave propagation based on Maxwell’s and bio-heat equations to obtain consistent results. These obtained models allowed us to evaluate the spatial profile of induced current and temperature of biological tissue during exposure to electromagnetic waves generated by this system. The simulation 2D results obtained from computer tools show that the temperature variation and current induced by the electromagnetic field can have a very significant influence on the life of biological tissue. The paper provides a comprehensive analysis using advanced mathematical models to evaluate the influence of electromagnetic fields. The findings have direct implications for workplace safety, potentially influencing standards and regulations concerning electromagnetic exposure in industrial settings.
基金Project(2011DFB70230)supported by State International Cooperation Program of ChinaProject(N110403003)supported by Basic Research Foundation of Education Ministry of China
文摘Artificial bone with porous structure is crucial for tissue scaffold and clinic implants.Scaffold provides structure support for cells and guides tissues regeneration for final tissue structure.A computational aided process of porous bone modeling was developed which described the design and fabrication of tissue scaffolds by considering intricate architecture,porosity and pore size.To simulate intricate bone structure,different constructive units were presented.In modeling process,bone contour was gotten from computed tomography(CT)images and was divided into two levels.Each level was represented by relatively reconstructive process.Pore size distribution was controlled by using mesh generation.The whole hexahedral mesh was reduced by unit structure,when a 3D mesh with various hexahedral elements was provided.The simulation results show that constructive structure of porous scaffold can meet the needs of clinic implants in accurate and controlled way.
文摘Epithelial cell networks imply a packing geometry characterized by various cell shapes and distributions in terms of number of cell neighbors and areas.Despite such simple characteristics describing cell sheets,the formation of bubble-like cells during the morphogenesis of epithelial tissues remains poorly understood.This study proposes a topological mathematical model of morphogenesis in a squamous epithelial.We introduce a new potential that takes into account not only the elasticity of cell perimeter and area but also the elasticity of their internal angles.Additionally,we incorporate an integral equation for chemical signaling,allowing us to consider chemo-mechanical cell interactions.In addition to the listed factors,the model takes into account essential processes in real epithelial,such as cell proliferation and intercalation.The presented mathematical model has yielded novel insights into the packing of epithelial sheets.It has been found that there are two main states:one consists of cells of the same size,and the other consists of“bubble”cells.An example is provided of the possibility of accounting for chemo-mechanical interactions in a multicellular environment.The introduction of a parameter determining the flexibility of cell shapes enables the modeling of more complex cell behaviors,such as considering change of cell phenotype.The developed mathematical model of morphogenesis of squamous epithelium allows progress in understanding the processes of formation of cell networks.The results obtained from mathematical modeling are of significant importance for understanding the mechanisms of morphogenesis and development of epithelial tissues.Additionally,the obtained results can be applied in developing methods to influence morphogenetic processes in medical applications.
文摘A modeling strategy to predict the ability of surgical clips to achieve mechanical hemostasis when applied to the cut edge of a thick and muscular tissue is presented in this work. Although such a model may have broad utility in the design of hemostatic clips and other surgical and wound closure applications, our particular focus was on uterine closure following a Cesarean delivery. Mechanical closure of a blood vessel, which is the first step in the hemostatic process, is established when the compressive forces on the outer surface of a blood vessel are sufficient to overcome the local blood pressure and collapse the vessel. For thick tissue, forces applied to the tissue surface set up a stress distribution within the tissue that, if sufficient to mechanically close all vessels, will lead to cessation of local blood flow. The focus of the current work was on utilization of a planar and nonlinear finite element model to predict the pressure distribution within uterine tissue under the influence of hemostatic clips. After experimental model validation with a polymer tissue phantom, design curves were numerically developed, which consisted of the clip force necessary to achieve hemostasis for a given thickness tissue as well as the resulting deformed tissue thickness. Such curves could form the basis for a preliminary clip design, which would provide initial design guidance before more expensive experimental studies were required.
基金This work was supported by the National Institutes of Health(R00CA201603,R21EB025270,R21EB026175,R01EB028143)the Brigham Research Institute.
文摘Paper devices have recently attracted considerable attention as a class of cost-effective cell culture substrates for various biomedical applications.The paper biomaterial can be used to partially mimic the in vivo cell microenvironments mainly due to its natural three-dimensional characteristic.The paper-based devices provide precise control over their structures as well as cell distributions,allowing recapitulation of certain interactions between the cells and the extracellular matrix.These features have shown great potential for the development of normal and diseased human tissue models.In this review,we discuss the fabrication of paper-based devices for in vitro tissue modeling,as well as the applications of these devices toward drug screening and personalized medicine.It is believed that paper as a biomaterial will play an essential role in the field of tissue model engineering due to its unique performances,such as good biocompatibility,eco-friendliness,cost-effectiveness,and amenability to various biodesign and manufacturing needs.
文摘The main objective of this proposed article is to provide explanations to justify the validity of the results of the studies of the interaction between the electromagnetic fields and the human body. It can also find direct applications in the characterization and modeling of the macroscopic electrical properties of the biological media for assessing the effects of fields induced by electromagnetic radiation sources in the human body to set up new standards <span>on the Human exposure to electromagnetic fields. To do this, we have taken into account the different physical phenomena of propagation of a hyper-frequency electromagnetic plane wave and on the other hand, the expe</span>rimental values <span></span><span><span><span style="font-family:;" "="">in order to model the electrical behavior of human biological tissues based on an equivalent electronic circuit model composed of capacities, resistance and reel, which assimilates the biological tissues of the skin, grease, blood. This model using the characteristic impedance of the dielectric support makes it possible to evaluate the voltage induced by the electromagnetic waves of the hyper-frequencies in the studied biological system. The results of the simulations obtained from computer tools demonstrate that the hyper-frequency electromagnetic waves can result in an elevation of the electrical potential of the biological tissues. Despite this potential is a decreasing function of the penetration depth.</span></span></span>
基金Natural Science Foundation of China,Grant/Award Number:22005077Heilongjiang Provincial Universities Basal Research Foundation-Youth Innovation Talent Project,Grant/Award Number:145109210Natural Science Foundation of Heilongjiang Province of China,Grant/Award Number:LH2021B032。
文摘Digital light processing(DLP)-based bioprinting technology has recently aroused considerable concerns as a strategy to deliver biomedical materials and/or specific cells to create sophisticated structures for various tissue modeling and regeneration.In this review,we display a concise introduction of DLP bioprinting,and a further discussion on the design and manufacture of DLP(bio)printer with varied bioinks and their biomedical applications toward drug screening,disease modeling,tissue repair,and regenerative medicine.Finally,the advantages,challenges,and perspectives of the DLP printing platforms are detailed.It is believed that DLP bioprinting will play a decisive role in the field of tissue model and regenerative medicine,mainly due to its time-efficient,higher resolution,and amenability to automation for various tissue needs.
基金supported by the Academic Discipline Project(No.S30602)the Shanghai Science Foundation of China(No.08ZR1409300)
文摘This paper presents a novel method for assisting surgeons in automatically computing an optimal surgical plan by directly specifying the desired correction to a facial outline. First, the desired facial appearance is designed using a 3D sculpturing tool, while the cut regions of the skull are defined based on facial anatomy. Then, the deformation of the face meshes is performed using an improved biomechanical model in which virtual external forces are driven by the displacements corresponding to the differences of node coordinates between the original and specified face meshes, and free nodes and fixed nodes are defined in terms of the contact surfaces between the soft tissues and the bones within the cut regions. Finally, the shape of the contact surfaces is updated following the deformation of the soft tissues. After registering the deformable contact surfaces and the cut surfaces, the final positions of the cut bones are estimated. Evaluation of preliminary experimental results quantitatively shows the effectiveness of the proposed approach.
文摘This article introduces a new biomedical / open surgical instrument to assist surgeon in applying surgical clips to patient’s body tissue and blood vessel during surgical processes. The new clip delivery system is designed to better the clip’s distal advance through internal clip channel, jaw guiding track, and all other transition areas to keep surgical clip from accidental shooting out during clip’s distal move into jaws. Currently the clip distal move in normal surgical instrument is usually driven by compression springs and some complains of clip accidental drop-off were recorded in surgical procedures. Because higher request of dimensional tolerance and better component surface quality are needed in case the compression springs are used as driven force, a little dimensional devia-tion or less qualified part surface produced from manufacturing processes will potentially cause surgical clip device malfunction or misfiring of the clips. It is clearly known that the jaws can seriously sever or damage patient’s blood ves-sel or body tissue if there is no clip inside the jaws due to accidental clip drop-off, when surgeons close instrument handles. The improved internal system design in this new open surgical instrument can prevent clip from accidental drop-off because of well guided and controlled clip distal move through internal clip channel and track. Besides the operational force to fully form clip is lower than existing surgical clip devices due to better mechanical advantage in this new instrument design. In addition to the above, manufacturing and product cost can be decreased since lower requirement of dimensional tolerance and surface quality of instrumental parts is allowed in this new surgical instrument design. This new instrumental prototype is build upon the analysis of computer aided modeling and simulation to prove its good mechanical advantage, feasible function, reliable performance. The preliminary results of instrument fir-ing force from both computer aided modeling and prototype testin
基金the National Natural Science Foundation of China (No. 51178265)
文摘This paper studied experimentally and theoretically the biomechanical properties of skin with laser influence. Different types of tensile tests of the porcine skin in vitro were conducted to study effect of the laser, tensile strength, stress-strain relationship, influence of skin's anisotropy and different regions, repetitive loading and stress-relaxation. A modeling of skin was developed according to the experimental results. The modeling provided insights into the important structure-function relationship in skin tissue with the laser effect. The nonlinear and anisotropic mechanical responses of skin are largely due to varying degree of fiber undulation which is effected by laser and outside forces. By introducing the laser factor into the constitutive modeling, the skin's biomechanical properties and the mechanism of the skin repair with laser were discussed.
文摘Tissue engineering’s main goal is to regenerate or replace tissues or organs that have been destroyed by disease,injury,or congenital disabilities.Tissue engineering now uses artificial supporting structures called scaffolds to restore damaged tissues and organs.These are utilized to attach the right cells and then grow them.Rapid prototyping appears to be the most promising technology due to its high level of precision and control.Bone tissue replacement“scaffolding”is a common theme discussed in this article.The fused deposition technique was used to construct our scaffold,and a polymer called polylactic acids and soybean oil resin were used to construct our samples.The samples were then divided into two groups;the first group was left without immersion in the simulated body fluid and served as a control for comparison.The second group was immersed in the simulated body fluid.The results of the Field Emission Scanning Electron Microscope(FESEM),Energy Dispersive X-ray Spectroscopy(EDX)and X-ray diffraction(XRD)were utilized to interpret the surface attachment to ions,elements,and compounds,giving us a new perspective on scaffold architecture.In this study,an innovative method has been used to print therapeutic scaffold that combines fused deposition three-dimensional printing with ultraviolet curing to create a high-quality biodegradable polymeric scaffold.Finally,the results demonstrate that adding soybean oil resin to the PLA increased ion attachment to the surface while also attracting tricalcium phosphate formation on the surface of the scaffold,which is highly promising in bone tissue replacement.In conclusion,the soybean oil resin,which is new in the field of bone tissue engineering,shows magnificent characteristics and is a good replacement biopolymer that replaces many ceramic and polymeric materials used in this field that have poor morphological characteristics.
